Conventionally, to facilitate winding a steel wire around a molding drum to mold a bead core, a deforming apparatus is used to deform the steel wire in correspondence with a desired diameter of the bead core. For example, deforming apparatuses described in Patent Documents 1 and 2 each include a deforming roller on which a steel wire is mounted in a curved manner and a movement device that moves the deforming roller with respect to the molding drum.
The movement device of Patent Document 1 rotates a support plate, which supports the deforming roller. The support plate is rotated to move the deforming roller with respect to the molding drum. The movement device of Patent Document 2 moves the deforming roller to change the distance between the deforming roller and the molding drum. In this manner, by moving the deforming roller, the deforming apparatus of each of Patent Documents 1 and 2 changes the length by which a steel wire is mounted on the deforming roller in a curved manner. The greater the length of such curved-mounting with respect to the deforming roller, the greater the deforming intensity of the steel wire.